A former Navy sailor is suspected of sending possibly poison-filled packages to the Pentagon

FILE PHOTO: An aerial view of the Pentagon building in Washington
Thomson Reuters

A former Navy sailor is believed to be behind suspicious packages sent to the the secretary of defense and the Navy's top admiral at the Pentagon, US officials revealed.

Packages were also sent to the White House and Senator Ted Cruz's office in Texas as part of what investigators suspect was a coordinated effort.

The packages sent to the Pentagon initially tested positive for ricin, a substance which can be poisonous in certain forms.

The incidents are still under investigation.

A former Navy sailor is believed to have sent suspicious, potentially poison-filled packages to the Pentagon, US officials told Fox News on Wednesday.

The suspicious packages, which tested positive for ricin, a substance that can be deadly to someone exposed to purified powder, were intercepted in the mail room at the Pentagon on their way to Secretary of Defense James Mattis and Chief of Naval Operations Admiral John Richardson. The packages included a return address that reportedly led investigators to a suspect, whose name and motive are unknown at this time.

"On Monday, the Pentagon Force Protection Agency detected a suspicious substance during mail screening at the Pentagon's remote screening facility," the Pentagon told Business Insider in a statement Tuesday. "The envelopes were taken by the FBI this morning for further analysis."

"All USPS mail received at the Pentagon mail screening facility yesterday is currently under quarantine and poses no threat to Pentagon personnel," the statement from Pentagon spokesman Col. Rob Manning further explained.

Packages were also sent to the White House and Sen. Ted Cruz's office in Texas as part of what investigators believe is a coordinated effort. All of the packages were intercepted before they could arrive at their intended destinations, and the Secret Service tipped off the Pentagon.

The FBI is spearheading the investigation into the suspicious deliveries. The Secret Service is, according to Fox News, "working jointly with our law enforcement partners to fully investigate this matter."